1. Technical Field
Embodiments generally relate to input/output (IO) interconnects. More particularly, embodiments relate to optical IO interconnects having a wavelength division multiplexed (WDM) architecture and clock and data recovery (CDR) clock sharing receiver.
2. Discussion
As input output (IO) interconnect speeds continue to increase in server links such as processor-to-processor, processor-to-memory and peripheral IO connections, link distances may be limited by signal integrity (SI) concerns. Indeed, link distance limitations can be particularly challenging in datacenters and high performance computing (HPC) systems in which large scale IO connectivity is needed between servers, routers and switches.
While optical IO interconnects may alleviate distance constraints to a certain extent, there remains considerable room for improvement. For example, a conventional optical serial link may be based on a parallel architecture carrying N-bit data lanes over N-number of optical fiber strands in each direction, wherein skew between the data lanes of the end-to-end optical link can be considerably large and/or unpredictable due to variations in fiber manufacturing and assembly processes. As a result, each receiver lane may use a clock and data recovery (CDR) module to recover the clock of the lane in question so that data may be correctly latched in the receiver. The use of N-CDR modules in the receiver, however, may lead to increased power consumption, which can be a significant concern in large scale computing architectures such as datacenters and HPC systems.